Axoid force mechanism

ABSTRACT

An axoid force mechanism has first and second end elements, at least one of the end elements being arranged for progressive movement. First and second stocks are respectively on the first and second end elements, the first and second stocks respectively having first and second supporting surfaces that are at least portions of circular cylinders. A first intermediate member has first and second supporting surfaces that are at least portions of circular cylinders respectively engaged with the first and second supporting surfaces of the first and second stocks for rolling thereon when the one of the end elements moves progressively.

BACKGROUND OF THE INVENTION

This invention relates to machinery and, more particularly to mechanismsfor transformation of force and speed parameters of progressive androtary movements.

Lever mechanisms raising forces within one work cycle and transformingprogressive and rotary movements are widely used (see Artobolevsky I.I., "Theory of Machines and Mechanisms", Moscow: "Science", 1975).

There exists the lever mechanism (Artobolevsky I. I., "The mechanisms inmodern technique," Moscow: "Science", vol. 2, 1979, p. 15, example 872),consisting of an intermediate member with two end elements forprogressive movements. Forces on the end element, speed of movementthereof and angular velocity of the intermediate member in such amechanism are defined by following formulas:

    P.sub.2 =P.sub.1 (sin α.sub.1 /sin α.sub.2)-ΔP;

    V.sub.2 =V.sub.1 (cos α.sub.1 /cos α.sub.2);

    ω=V.sub.1 /(L sin α.sub.1)=V.sub.2 /(L sin α.sub.2);(1)

wherein: P₂, P₁ are forces on the end elements; V₂, V₁ are speedsthereof respectively; α₂ α₁ are angles between the plane containing thegeometric axes of supporting surfaces of the end elements and directionsof the end element movement; ΔP is a reduction of force due to friction;and ω is a angular velocity of the intermediate member.

In such mechanisms the forces acting on the end elements may be balancedby torque acting on the intermediate member in accordance with formula:

    M+P.sub.1 L sin α.sub.1 +P.sub.2 L sin α.sub.2 +Δ=0;

where M is a torque on the intermediate member; Δ is loss of force ortorque due to friction, and other symbols are as defined above.

Such a mechanism can be used for mutual transformation of progressiveand rotative movements with respective transformation of forces andtorques.

Without taking into consideration loss due to friction, the force on oneof the end elements may be unlimitedly great while the mechanism is in acertain position, whereas the force on the other end element or torqueon the intermediate member is limited.

However sliding of loaded supporting surfaces causes intensivewear-and-tear, expenses to maintain reliability, and substantialreduction of the force capability of such mechanism. These deficienciescause the use of antifriction materials, compound lubricating systemsand ball or roller bearings. But the supporting surfaces continue to bethe most vulnerable parts of such mechanisms.

SUMMARY OF THE INVENTION

Therefore an object of this invention is to reduce the losses and toraise force and speed capabilities of such a mechanism fortransformation of progressive and rotary movement by elimination ofsliding friction.

Elimination of sliding friction is provided by supporting surfaces thatroll on each other without slipping when the end elements makeprogressive movements. For this the axis of mutual turning of the priorend element and the intermediate member is replaced by a line of contactbetween supporting surfaces.

We have named this mechanism "Axoid Force Mechanism" (hereinafter AFM).

In the connections of the AFM slipping is theoretically eliminated.Therefore wear-and-tear, loss of power, and sensibility to lubricationare substantially reduced. Force capacity and endurance are increased asa result of the use of materials with high contact endurance for whichantifriction properties are no longer essential.

The intermediate member can consist of several contact elements, whichmay be placed either in parallel or in succession.

It is necessary that the number of contact elements and radiuses of asupporting axoids curvature in the each succession thereof meet thefollowing formula for the end elements not to slip in supporting theprogressive movement, including the end elements: ##EQU1## wherein: k isnumber of contact elements in that succession; ρ.sub.(2j-1), ρ.sub.(2j)are curvature radiuses of the supporting axoids in the area of j-thcontact.

Circular cylinder supporting surfaces are most preferable for the endelements and intermediate member.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a front elevational schematic view of a first embodiment in aposition where forces on end elements are approximately equal.

FIG. 2 is a front elevational schematic view of a second embodiment in aposition where forces on end elements are approximately equal.

FIG. 3 is a front elevational schematic view of a third embodiment in aposition where forces on end elements are approximately equal.

FIG. 4 is a front elevational schematic view of the first embodiment ina position where the force on one of the end elements is maximum and theforce on the other end element or torque on its supporting surface isconfined.

FIG. 5 is a front elevational schematic view of the first embodimentwith additional structure to give or receive torque from an intermediatemember.

FIG. 6 is a front elevational schematic view of another embodiment.

DETAILED DESCRIPTION OF INVENTION

In the embodiment shown in FIG. 1 the end element 1, which receivesprogressive movement in a direction from a drive (not shown), isprovided with a stock 2 with supporting surface 3 of circular cylinderform or, more particularly, a portion thereof. The end element 6, whichis progressively movable in a direction perpendicular to the directionof the end element 1, is provided with a similar stock 4 and supportingsurface 5.

The intermediate member 7 of circular cylinder form is placed betweenthe stocks 2 and 4. One portion of its supporting surface 8 is incontact with the supporting surface 3 of the stock 2 and an oppositeportion of its supporting surface 9 is in contact with the supportingsurface 5 of the stock 4. The intermediate member 7 is fixed between thestocks 2 and 4 by retaining elements 10, which in this embodiment arehinged to axes of the stocks 2 and 4.

In the embodiment shown in FIG. 2 the intermediate member 11 is a unitof two plates 12 connected to each other and provided with oppositeinternally cylindrical supporting surfaces 13 and 14. The supportingsurface 13 contacts the supporting surface 3 of the stock 2 and thesupporting surface 14 contacts with the supporting surface 5 of thestock 4.

Rotary movement can be obtained from the intermediate member 7 when theend elements 1 and 6 are driven in their progressive movements or theend elements 1 and 6 can be driven when the intermediate member 7 isprovided with torque by a drive element 15 (see FIG. 5), which contactsone of the supporting surfaces 8 or 9 of the intermediate member 7 witha supporting surface 16.

All or some of the supporting surfaces 3, 5, 8, 9, 16 may be providedwith teeth (not shown) to gear with each other.

The AFM can be used as shown in FIG. 6., for example. A crank mechanism17 is connected with end element 1, which is provided with a stock 2with the supporting surface 3 and is the first element of further AFMs18 and 19. The second end element of AFM 19 is rigidly connected to aframe. The second end element of AFM 20 is a progressively movable endelement 20.

The AFM works as follows:

The force, which acts on the end element 1, moves it together with itsstock 2. Therefore the supporting surface of its intermediate member 7rolls on supporting surface 3 of stock 2, and the opposite supportingsurface 9 of the intermediate member transmits this movement to stock 4by rolling of its supporting surface 9 on the supporting surface 5. Thisinteraction of the supporting surfaces 3-8 and 9-5 takes place byrolling without slipping.

FIG. 4 shows the state of the AFM of FIG. 1, when in accordance withformulas (1), a speed of the progressive movement of the end element 6is zero and the force on end element 6 is maximal whereas the force onend element 1 is zero.

In the embodiment of FIGS. 2 and 3, when the end element 1 moves in thereverse direction (left in the Figs.), then the stock 2 drags theintermediate member 11 as its supporting surface 13 rolls on thesupporting surface 3 of the stock 2. The movement of the intermediatemember 11 causes rolling of the supporting surface 14 on the supportingsurface 5 of the stock 4 and thereby moves the end element 6 down.

If great forces for returning the AFM to its initial position are notnecessary, then the AFM need not contain the second intermediate member7 shown in FIG. 3, and its return can be made by retaining elements 10as shown in in FIG. 2.

It is obvious that the intermediate member 7 makes a complicatedmovement: turning around its own geometrical axis, which moves in acircle, whereas the end elements 1 and 6 only make progressivemovements. Therefore, constructing the supporting surfaces 3, 5, 8, 9and 16 to carry a torque allows the AFM to give or receive power to orfrom rotative movement of the drive element 15.

An AFM (for example such as shown in FIG. 6) can function as follows.Power is transmitted by a crank mechanism 17 to the end element 1, whichis common for AFMs 18 and 19. That movement is transmitted to workingelement 20 with force increasing to the end of the stroke.

What is claimed is:
 1. An axoid force mechanism, comprising two endelements connected with an intermediate member for transmission ofmovement through supporting surfaces that roll on each other with forcesand speeds in accordance with formulas:

    P.sub.2 =P.sub.1 (sin α.sub.1 /sin α.sub.2)-ΔP; V.sub.2 =V.sub.1 (cos α.sub.1 /cos α.sub.2);

where: P₂, P₁ are forces on the end elements; V₂,V₁ are speeds of theend elements; α₂, α₁ are angles formed by planes passing through axes ofthe supporting surfaces defining directions of movements of the endelements, and ΔP is a reduction of force due to friction, characterizedin that the intermediate member consists of at least one succession ofcontact elements having supporting surfaces, which as well as thesupporting surfaces of the end elements, are constructed and placed so,that, when one of the end elements moves progressively, the supportingsurfaces roll without slipping to transmit forces and movement to theother of the end elements, wherein radii of the supporting surfaces ineach succession satisfy the following formula: ##EQU2## where: k isnumber of contact elements in this succession; and ρ(2j-1), ρ(2j) arecurvature radii of the supporting surfaces in area of j-th contact. 2.The axoid force mechanism as defined in claim 1, characterized in thatthe supporting surfaces are at least portions of circular cylinders andare placed so that their geometrical axes and lines of their contact areplaced in a common plane.
 3. The axoid force mechanism defined in claim2, characterized in that the supporting surfaces have gear-likestructures for torque transmission.
 4. The axoid force mechanism asdefined in claim 2, characterized in that the intermediate member hassupporting surfaces between supporting surfaces of the end elements forcontact with them, and further comprising retaining elements forsupporting the end elements and intermediate member.
 5. The axoid forcemechanism defined in claim 4, characterized in that the supportingsurfaces have gear-like structures for torque transmission.
 6. The axoidforce mechanism as defined in claim 2, and further comprising a secondintermediate member, wherein supporting surfaces of one of theintermediate elements are between and contacting supporting surfaces ofthe end elements which are between and contacting supporting surfaces ofthe second intermediate member.
 7. The axoid force mechanism defined inclaim 6, characterized in that the supporting surfaces have gear-likestructures for torque transmission.
 8. The axoid force mechanism asdefined in claim 1, characterized in that the intermediate member hassupporting surfaces between supporting surfaces of the end elements forcontact with them, and further comprising retaining elements forsupporting the end elements and intermediate member.
 9. The axoid forcemechanism defined in claim 8, characterized in that the supportingsurfaces have gear-like structures for torque transmission.
 10. Theaxoid force mechanism defined in claim 1, characterized in that thesupporting surfaces have gear-like structures for torque transmission.11. An axoid force mechanism, comprising:first and second end elements,at least one of the end elements being arranged for progressivemovement; first and second stocks respectively on the first and secondend elements, the first and second stocks respectively having first andsecond supporting surfaces that are at least portions of circularcylinders; and a first intermediate member having first and secondsupporting surfaces that are at least portions of circular cylindersrespectively engaged with the first and second supporting surfaces ofthe first and second stocks for rolling thereon when the one of the endelements moves progressively.
 12. The axoid force mechanism according toclaim 11, wherein the first and second supporting surfaces of theintermediate member are one of convex and concave.
 13. The axoid forcemechanism according to claim 12, and further comprising a secondintermediate member having first and second supporting surfaces that areat least portions of circular cylinders respectively engaged with thefirst and second supporting surfaces of the first and second stocks forrolling thereon when the one of the end elements moves progressively.14. The axoid force mechanism according to claim 12, and furthercomprising retaining elements connecting the first and second stocks.15. The axoid force mechanism according to claim 14, and furthercomprising a second intermediate member having first and secondsupporting surfaces that are at least portions of circular cylindersrespectively engaged with the first and second supporting surfaces ofthe first and second stocks for rolling thereon when the one of the endelements moves progressively.
 16. The axoid force mechanism according toclaim 15, wherein at least the first supporting surface of the firstintermediate member and stock are engaged with gear teeth.
 17. The axoidforce mechanism according to claim 16, and further comprising a driveelement engaging the first intermediate member for receiving orimparting rotation.
 18. The axoid force mechanism according to claim 12,wherein at least the first supporting surface of the first intermediatemember and stock are engaged with gear teeth.
 19. The axoid forcemechanism according to claim 12, and further comprising a drive elementengaging the first intermediate member for receiving or impartingrotation.
 20. The axoid force mechanism according to claim 11, andfurther comprising retaining elements connecting the first and secondstocks.
 21. The axoid force mechanism according to claim 20, and furthercomprising a second intermediate member having first and secondsupporting surfaces that are at least portions of circular cylindersrespectively engaged with the first and second supporting surfaces ofthe first and second stocks for rolling thereon when the one of the endelements moves progressively.
 22. The axoid force mechanism according toclaim 20, wherein at least the first supporting surface of the firstintermediate member and stock are engaged with gear teeth.
 23. The axoidforce mechanism according to claim 20, and further comprising a driveelement engaging the first intermediate member for receiving orimparting rotation.
 24. The axoid force mechanism according to claim 11,and further comprising a second intermediate member having first andsecond supporting surfaces that are at least portions of circularcylinders respectively engaged with the first and second supportingsurfaces of the first and second stocks for rolling thereon when the oneof the end elements moves progressively.
 25. The axoid force mechanismaccording to claim 24, wherein at least the first supporting surface ofthe first intermediate member and stock are engaged with gear teeth. 26.The axoid force mechanism according to claim 24, and further comprisinga drive element engaging the first intermediate member for receiving orimparting rotation.
 27. The axoid force mechanism according to claim 11,wherein at least the first supporting surface of the first intermediatemember and stock are engaged with gear teeth.
 28. The axoid forcemechanism according to claim 27, and further comprising a drive elementengaging the first intermediate member for receiving or impartingrotation.
 29. The axoid force mechanism according to claim 11, andfurther comprising a drive element engaging the first intermediatemember for receiving or imparting rotation.